This proposal seeks funds for the third and final year of a project whose goal is the establishment of the germfree dog as a research resource at the University of Wisconsin Gnotobiotic Laboratory. This grant is intended to augment the continuing institutional support for this resource. This project is training gnotobiotic animal caretakers in the techniques of rearing germfree dogs; is developing equipment and techniques needed to operate upon and conduct research with germfree dogs; is supplying animals and personnel necessary to conduct pilot studies using the adult gnotobiotic dog; is collecting data on the blood and serum chemistry values of the germfree dog; and is continuing to develop cost accounting data on the germfree dog so that realistic fee-for-service charges can be rendered to individual investigations in the future. This research resource is available to qualified investigators of this and other institutions.